Felix is sure his face is impressively red, at this point. The incorrigible fairy has been winding him up for half the evening, He's definitely not upset. On the contrary, it's proven a positive distraction for him.
Nilys has, at the moment, invited themself into Felix's lap, and judging by their grin, they're enjoying Felix's fluster a little too much. They place a palm flat against his chest with a giggle about the deer-in-the-headlights stare he's started giving them.
Something else rather suddenly catches Nilys' attention though. "Oh! What's that?" Before Felix can answer, their fingers have found the chain draped over his neck and pulled on it until the locket attached is exposed. They take hold of it with a curious expression.
"Oh... b-be careful with that, please. It's important to me."
"I will, don't worry." Nilys' fingers brush over it delicately, their eyes now not moving away from the pendant in spite of how focused they had been on tormenting the man just a moment ago. "Oh wow. This is a pretty powerful charm. I'm surprised you have something like that."
"Huh? Oh. Right. I found it in an antiques store a few years back... I really just bought it because of how cursed it looked. But I guess it's lucky that it turned out to be something that protects me from possession."
Nilys hums thoughtfully, not responding to Felix for long enough that he starts to wonder if they heard them. Finally, they tap their finger against the locket a couple of times. "That's not what this is."
"Nope. It's, um, what you might call a dampening spell? This is a really complicated one, though, I'd love to meet the mage who pulled it off! So, like, I think it only affects spirits? And it actually turns their energy back against them, soooooo the effect is stronger with a really powerful ghost. It's sort of a... suppressor? You can think of it like a field of calm is being generated around you when you wear it. A really strong spirit would like, be completely overpowered by the magic in this locket, so it is good protection, just not the way you thought."
Felix is silent for a moment, wondering why it never occurred to him to ask someone about it. He realizes he badly needs to evaluate his life and make sure there's nothing else he needs to bring up with someone who might know more than he does. "Oh. Well... thank you for telling me."
Nilys, still thoughtfully examining it, speaks uncertainly a moment later. "That's actually not everything, but... sorry! I can't tell what else is going on here. I think there's at least one other enchantment that's dormant right now, but I can't pick up on it and I'm not sure what activates it. It's really cool that you have this, though!"
Nilys beams at him, and Felix laughs uncertainly in the absence of knowing what to do or say. "Yeah, I guess it really is."
He's not sure if he should be insulted or relieved that their attention was turned away from teasing him this easily.